Recurrent selection is a technique used in plant breeding to improve the genetic makeup of a population over multiple generations. It involves selecting and mating individuals with desirable traits, then selecting and mating their offspring with additional desirable traits, and so on, over several breeding cycles. There are several reasons why recurrent selection is employed in plant breeding:

Improvement of complex traits: Many desirable traits in plants are controlled by multiple genes and are influenced by environmental factors. Recurrent selection allows breeders to gradually accumulate favorable alleles for these complex traits over multiple generations, leading to more significant improvements.

Genetic diversity: Recurrent selection helps maintain genetic diversity within a breeding population. By continually introducing new genetic material from diverse sources, breeders can avoid the loss of genetic variability that can occur with repeated rounds of selection.

Adaptation to changing environments: As environmental conditions change over time, plants need to adapt to new challenges such as pests, diseases, and climate fluctuations. Recurrent selection allows breeders to continually select for traits that confer resilience and adaptability to changing environmental conditions.

Reduction of inbreeding depression: Inbreeding depression, which occurs when closely related individuals are mated, can lead to reduced vigor and productivity in offspring. Recurrent selection helps minimize inbreeding depression by periodically introducing new genetic material into the breeding population, thus maintaining hybrid vigor.

Cumulative genetic gain: Over successive generations of recurrent selection, cumulative genetic gains can be achieved as favorable alleles are accumulated and combined in the breeding population. This gradual improvement in the genetic makeup of the population leads to the development of superior plant varieties.

Overall, recurrent selection is a powerful tool in plant breeding that enables breeders to systematically improve the genetic characteristics of plant populations, leading to the development of improved cultivars with desirable traits for agricultural production, environmental sustainability, and human nutrition.